qemu-kvm-viommu.md

Enable Virtual IOMMU on Virtual Machine (QEMU-KVM)

1. Create VM

Q35 platform is required. For this documentation, the guest OS used is Ubuntu 18.04 server and OVMF UEFI.

2. Edit the VM XML definition

Using:

virsh edit <vm-name>

In features section add:

<ioapic driver='qemu'/>

And in devices section add:

<iommu model='intel'>
    <driver intremap='on'/>
</iommu>

3. Edit the VM GRUB file

Add intel_iommu=on to GRUB_CMDLINE_LINUX_DEFAULT variable in /etc/default/grub file. And then update by running sudo update-grub command.

4. Reboot the VM and then verify IOMMU groups exists in it

The following script can be used to list groups and their devices.

bash -c '
    for group in $(ls -1 /sys/kernel/iommu_groups); do
        echo "group-${group}:"
        for device in $(ls -1 /sys/kernel/iommu_groups/${group}/devices); do
            echo "  - $(lspci -nnks ${device})"
        done
    done
'

Example output:

group-0:
  - 00:00.0 Host bridge [0600]: Intel Corporation 82G33/G31/P35/P31 Express DRAM Controller [8086:29c0]
	Subsystem: Red Hat, Inc. QEMU Virtual Machine [1af4:1100]
group-1:
  - 00:01.0 VGA compatible controller [0300]: Red Hat, Inc. QXL paravirtual graphic card [1b36:0100] (rev 04)
	Subsystem: Red Hat, Inc. QEMU Virtual Machine [1af4:1100]
	Kernel driver in use: qxl
	Kernel modules: qxl
group-2:
  - 00:02.0 PCI bridge [0604]: Red Hat, Inc. QEMU PCIe Root port [1b36:000c]
	Kernel driver in use: pcieport
	Kernel modules: shpchp
  - 00:02.1 PCI bridge [0604]: Red Hat, Inc. QEMU PCIe Root port [1b36:000c]
	Kernel driver in use: pcieport
	Kernel modules: shpchp
  - 00:02.2 PCI bridge [0604]: Red Hat, Inc. QEMU PCIe Root port [1b36:000c]
	Kernel driver in use: pcieport
	Kernel modules: shpchp
  - 00:02.3 PCI bridge [0604]: Red Hat, Inc. QEMU PCIe Root port [1b36:000c]
	Kernel driver in use: pcieport
	Kernel modules: shpchp
  - 00:02.4 PCI bridge [0604]: Red Hat, Inc. QEMU PCIe Root port [1b36:000c]
	Kernel driver in use: pcieport
	Kernel modules: shpchp
  - 00:02.5 PCI bridge [0604]: Red Hat, Inc. QEMU PCIe Root port [1b36:000c]
	Kernel driver in use: pcieport
	Kernel modules: shpchp
  - 01:00.0 PCI bridge [0604]: Red Hat, Inc. Device [1b36:000e]
	Kernel driver in use: shpchp
	Kernel modules: shpchp
  - 02:01.0 Audio device [0403]: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) High Definition Audio Controller [8086:2668] (rev 01)
	Subsystem: Red Hat, Inc. QEMU Virtual Machine [1af4:1100]
	Kernel driver in use: snd_hda_intel
	Kernel modules: snd_hda_intel
  - 03:00.0 Ethernet controller [0200]: Red Hat, Inc. Virtio network device [1af4:1041] (rev 01)
	Subsystem: Red Hat, Inc. Virtio network device [1af4:1100]
	Kernel driver in use: virtio-pci
  - 04:00.0 Communication controller [0780]: Red Hat, Inc. Virtio console [1af4:1043] (rev 01)
	Subsystem: Red Hat, Inc. Virtio console [1af4:1100]
	Kernel driver in use: virtio-pci
  - 05:00.0 SCSI storage controller [0100]: Red Hat, Inc. Virtio block device [1af4:1042] (rev 01)
	Subsystem: Red Hat, Inc. Virtio block device [1af4:1100]
	Kernel driver in use: virtio-pci
  - 06:00.0 Unclassified device [00ff]: Red Hat, Inc. Virtio memory balloon [1af4:1045] (rev 01)
	Subsystem: Red Hat, Inc. Virtio memory balloon [1af4:1100]
	Kernel driver in use: virtio-pci
group-3:
  - 00:1d.0 USB controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1 [8086:2934] (rev 03)
	Subsystem: Red Hat, Inc. QEMU Virtual Machine [1af4:1100]
	Kernel driver in use: uhci_hcd
  - 00:1d.1 USB controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #2 [8086:2935] (rev 03)
	Subsystem: Red Hat, Inc. QEMU Virtual Machine [1af4:1100]
	Kernel driver in use: uhci_hcd
  - 00:1d.2 USB controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #3 [8086:2936] (rev 03)
	Subsystem: Red Hat, Inc. QEMU Virtual Machine [1af4:1100]
	Kernel driver in use: uhci_hcd
  - 00:1d.7 USB controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #1 [8086:293a] (rev 03)
	Subsystem: Red Hat, Inc. QEMU Virtual Machine [1af4:1100]
	Kernel driver in use: ehci-pci
group-4:
  - 00:1f.0 ISA bridge [0601]: Intel Corporation 82801IB (ICH9) LPC Interface Controller [8086:2918] (rev 02)
	Subsystem: Red Hat, Inc. QEMU Virtual Machine [1af4:1100]
	Kernel driver in use: lpc_ich
	Kernel modules: lpc_ich
  - 00:1f.2 SATA controller [0106]: Intel Corporation 82801IR/IO/IH (ICH9R/DO/DH) 6 port SATA Controller [AHCI mode] [8086:2922] (rev 02)
	Subsystem: Red Hat, Inc. QEMU Virtual Machine [1af4:1100]
	Kernel driver in use: ahci
	Kernel modules: ahci
  - 00:1f.3 SMBus [0c05]: Intel Corporation 82801I (ICH9 Family) SMBus Controller [8086:2930] (rev 02)
	Subsystem: Red Hat, Inc. QEMU Virtual Machine [1af4:1100]
	Kernel modules: i2c_i801